Method of suppressing phased array far sidelobe bulge

Abstract

The present application relates to a method for suppressing far sidelobe bulge of a phased array, comprising the following steps: S100: setting a phase rotation granularity of a phased array to 2x2, and measuring a residual phase percentage of the phased array; S200: determining a phase rotation granularity of the phased array that meets an index requirement according to the residual phase percentage of the phased array and a pre-given far sidelobe bulge index; S300: dividing the phased array into a plurality of sub-arrays according to the phase rotation granularity that meets the index requirement, and determining a rotation phase of each sub-array; S400: applying the determined rotation phase to each sub-array of the phased array. The method for suppressing far sidelobe bulge of a phased array can significantly improve far sidelobe bulge, thereby improving communication performance.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and more specifically to a method for suppressing far-sidelobe bulges in a phased array. Background Technology

[0002] Limited by factors such as the complexity of geographical environments and deployment costs, traditional terrestrial cellular networks still have significant shortcomings in coverage, especially in remote areas such as oceans, deserts, plateaus, and polar regions. In order to build an integrated "space-air-ground" three-dimensional communication system and achieve continuous coverage of the entire space, including air, space, land, and sea, satellite communication, which complements traditional terrestrial cellular networks, has gradually become a hot topic in the industry in recent years, setting off a research wave in academia and industry.

[0003] Based on their orbital altitude, satellite communication systems are generally classified into three categories: Geostationary Earth Orbit (GEO), Medium Earth Orbit (MEO), and Low Earth Orbit (LEO). GEO operates at an altitude of approximately 35,786 kilometers, MEO at altitudes between 2,000 and 35,786 kilometers, and LEO typically at altitudes between several hundred and two thousand kilometers. At such high altitudes, satellites experience transmission path losses of at least 150 dB. To ensure successful air-to-ground communication, large-scale phased arrays must be deployed on the satellites to achieve the necessary signal-to-noise ratio (SNR) for demodulation.

[0004] Since circularly polarized antennas can effectively resist transmission uncertainties caused by factors such as terminal attitude changes, ionospheric effects, rain attenuation, and adjacent channel interference, phased arrays generally use circularly polarized antennas to enhance signal stability and anti-interference capabilities.

[0005] However, the rotating phase that produces circular polarization causes a bulge in the far sidelobes of the phased array beam. This bulge can lead to several problems: first, it affects transmit / receive isolation in certain spatial directions; second, it generates interference in undesirable directions; and third, it reduces power in desired directions. These issues degrade satellite communication performance and, in severe cases, can cause communication outages. Summary of the Invention

[0006] The purpose of this invention is to provide a method for suppressing the far sidelobe bulge of a phased array, so as to improve satellite communication performance.

[0007] To achieve the above objectives, the present invention provides a method for suppressing the bulge of the far sidelobe in a phased array, comprising the following steps:

[0008] S100: Set the phase rotation granularity of the phased array to 2×2 and measure the percentage of residual phase of the phased array.

[0009] S200: Determine the phase rotation granularity of the phased array to meet the index requirements based on the residual phase percentage of the phased array and the pre-given far sidelobe bulge index.

[0010] S300: Divide the phased array into multiple subarrays according to the phase rotation granularity that meets the index requirements, and determine the rotation phase of each subarray;

[0011] S400: Apply the determined rotation phase to each subarray of the phased array.

[0012] Optionally, step S100 specifically includes:

[0013] S110: Based on the 2×2 phase rotation granularity, the phased array is divided into multiple 2×2 subarrays, each of which includes 2×2 adjacent antenna elements.

[0014] S120: For each 2×2 subarray, an excitation is applied to each antenna element of the 2×2 subarray. The excitation amplitude of each antenna element is 1, and the phases are 0, 90, 180 and 270 degrees, respectively.

[0015] S130: Measure the phase at the air interface of each antenna in each 2×2 subarray as the residual phase of that antenna in the 2×2 subarray.

[0016] S140: Determine the percentage of residual phase of each antenna in the 2×2 subarray based on the residual phase of each antenna in the 2×2 subarray;

[0017] S150: Determine the residual phase percentage of the phased array based on the residual phase percentage of each 2×2 subarray.

[0018] Optionally, step S140 specifically includes:

[0019] S141: For each 2×2 subarray, divide the residual phase of each antenna element in the 2×2 subarray, except for the antenna element whose excitation phase is 0, by the excitation phase of the antenna to obtain the percentage of residual phase of the antenna element.

[0020] S142: Calculate the average of the residual phase percentages of each antenna element in each 2×2 subarray, excluding the antenna element whose excitation phase is 0, and use this average as the residual phase percentage of the 2×2 subarray.

[0021] Optionally, step S150 specifically includes:

[0022] Calculate the average of the residual phase percentages of each 2×2 subarray as the residual phase percentage of the phased array.

[0023] Optionally, step S200 specifically includes:

[0024] S210: Pre-obtain the parameter correspondence table between phase rotation granularity, residual phase percentage and distal sidelobe bulge;

[0025] S220: Based on the residual phase percentage of the phased array and the far sidelobe bulge index, find the phase rotation granularity that meets the index requirements in the parameter correspondence table.

[0026] Optionally, the row dimension of the parameter correspondence table is the phase rotation granularity, the column dimension is the residual phase percentage, and the cell value is the far sidelobe bulge under the corresponding phase rotation granularity and residual phase percentage.

[0027] Optionally, step S220 specifically includes:

[0028] S221: Find the residual phase percentage in the parameter correspondence table that is closest to and greater than or equal to the residual phase percentage of the phased array, and use it as the target residual phase percentage.

[0029] S222: Among the distal sidelobe bulges in the column of the target residual phase percentage in the parameter correspondence table, find the distal sidelobe bulge that is closest to the distal sidelobe bulge index and less than or equal to the distal sidelobe bulge index, and take it as the target distal sidelobe bulge.

[0030] S223: Determine the phase rotation granularity of the row where the target far sidelobe bulge is located, as the phase rotation granularity that meets the index requirements.

[0031] Optionally, in step S300, the rotation phase of each subarray is set as follows:

[0032] Each antenna element in each subarray is divided into four parts, and the phases of each antenna element in each part are the same, with any two adjacent parts having a phase difference of 90 degrees.

[0033] Optionally, the phases of the four parts are 0 degrees, 90 degrees, 180 degrees and 270 degrees respectively.

[0034] Optionally, the phases of the four parts are 0 degrees, 270 degrees, 180 degrees and 90 degrees respectively.

[0035] The method for suppressing distal sidelobe bulge of the present invention can significantly improve distal sidelobe bulge, thereby enhancing communication performance. Attached Figure Description

[0036] Figure 1 A schematic diagram of the rotation phase of a 2×2 subarray;

[0037] Figure 2 The beam pattern of a phased array with a phase rotation granularity of 2×2;

[0038] Figure 3A flowchart illustrating a method for suppressing the bulge of the far sidelobe of a phased array according to an embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of the rotation phase of a 4×4 subarray according to an embodiment of the present invention;

[0040] Figure 5 The beam pattern is a phased array with phase rotation granularity using the method of this embodiment of the invention. Detailed Implementation

[0041] The preferred embodiments of the present invention are given below with reference to the accompanying drawings and described in detail.

[0042] Satellite communication, with its wide coverage, rapid deployment, and strong resistance to terrain interference, has become a crucial infrastructure for future seamless global communication. To combat the significant path loss caused by long transmission distances, large-scale phased arrays are essential for satellite communication, and circularly polarized antennas are a vital means of obtaining stable signals. A phased array consists of multiple radiating elements (also called antenna elements). To achieve circular polarization, each antenna element can be divided into multiple subarrays, each containing multiple adjacent array elements (i.e., antenna elements). Then, for each antenna element in each subarray, a 90-degree clockwise or counterclockwise phase rotation is applied. For example, a 2×2 subarray (i.e., a 2×2 phase rotation granularity) includes four adjacent antenna elements, such as... Figure 1 As shown, clockwise (or counterclockwise) phase rotations of 0, 90, 180, and 270 degrees can be applied to these four antenna elements respectively to form circular polarization and obtain the optimal axial ratio.

[0043] like Figure 2 The image shows the phased array beam pattern measured in an anechoic chamber. Its main lobe points to 0 degrees, and the sidelobe attenuation is -30 dB. Figure 2 It can be seen that the amplitude attenuation of the side lobes in the range of 60 to 90 degrees away from the main lobe exceeds the attenuation index of 15 dB, and there is a significant bulging phenomenon, namely, the bulging of the distal side lobe.

[0044] To suppress the bulging of the distal accessory valve, such as Figure 3 As shown, this embodiment of the invention provides a method for suppressing the bulge of the far sidelobe of a phased array, which includes the following steps:

[0045] S100: Set the phase rotation granularity of the phased array to 2×2 and measure the residual phase percentage of the phased array.

[0046] Step S100 specifically includes:

[0047] S110: Based on the 2×2 phase rotation granularity, the phased array is divided into multiple 2×2 subarrays, each of which includes 2×2 adjacent antenna elements.

[0048] S120: For each 2×2 subarray, an excitation is applied to each antenna element of the 2×2 subarray. The excitation amplitude of each antenna element is 1, and the phases are 0, 90, 180 and 270 degrees, respectively.

[0049] S130: Measure the phase at the air interface of each antenna in each 2×2 subarray as the residual phase of that antenna in the 2×2 subarray.

[0050] S140: Determine the percentage of residual phase of each antenna in the 2×2 subarray based on the residual phase of each antenna in the 2×2 subarray;

[0051] S150: Determine the residual phase percentage of the phased array based on the residual phase percentage of each 2×2 subarray.

[0052] Step S140 specifically includes:

[0053] S141: For each 2×2 subarray, divide the residual phase of each antenna element in the 2×2 subarray, except for the antenna element whose excitation phase is 0, by the excitation phase of the antenna to obtain the percentage of residual phase of the antenna element.

[0054] S142: Calculate the average of the residual phase percentages of each antenna element in each 2×2 subarray, excluding the antenna element whose excitation phase is 0, and use this average as the residual phase percentage of the 2×2 subarray.

[0055] Step S150 specifically includes:

[0056] Calculate the average of the residual phase percentages of each 2×2 subarray as the residual phase percentage of the phased array.

[0057] S200: Determine the phase rotation granularity of the phased array to meet the index requirements based on the residual phase percentage of the phased array and the pre-given far sidelobe bulge index.

[0058] The far sidelobe bulge index refers to the maximum permissible far sidelobe bulge (i.e., the far sidelobe bulge cannot exceed the far sidelobe bulge index during phased array operation). The far sidelobe bulge index can be calculated based on the transmit / receive isolation index and the adjacent channel leakage suppression ratio index.

[0059] In some embodiments, step S200 specifically includes:

[0060] S210: Pre-obtain the parameter correspondence table of phase rotation granularity - residual phase percentage and far sidelobe bulge. The parameter correspondence table is a cross table of phase rotation granularity - residual phase percentage and far sidelobe bulge. The row dimension is phase rotation granularity, the column dimension is residual phase percentage, and the cell value is the far sidelobe bulge under the corresponding phase rotation granularity and residual phase percentage.

[0061] S220: Based on the residual phase percentage of the phased array and the far sidelobe bulge index, find the phase rotation granularity that meets the index requirements in the parameter correspondence table.

[0062] Table 1 is an exemplary parameter correspondence table between phase rotation granularity, residual phase percentage, and distal sidelobe bulge. As shown in Table 1, the row dimension is the phase rotation granularity, including 2×2, 4×4, 8×8, 16×16, and 32×32 phase rotation granularities, respectively; the column dimension is the residual phase percentage, including 1% to 10% residual phase percentages, respectively; and the cell represents the distal sidelobe bulge. For example, when the phase rotation granularity is 2×2 and the residual phase percentage is 1%, the distal sidelobe bulge is 2.5 dB.

[0063]

[0064] The parameter correspondence table can be obtained by simulating the phased array. The principle and steps are existing technologies and will not be elaborated here.

[0065] In some embodiments, step S220 specifically includes:

[0066] S221: Find the residual phase percentage in the parameter correspondence table that is closest to and greater than or equal to the residual phase percentage of the phased array, and use it as the target residual phase percentage.

[0067] S222: Among the distal sidelobe bulges in the column of the target residual phase percentage in the parameter correspondence table, find the distal sidelobe bulge that is closest to the distal sidelobe bulge index and less than or equal to the distal sidelobe bulge index, and take it as the target distal sidelobe bulge.

[0068] S223: Determine the phase rotation granularity of the row where the target far sidelobe bulge is located, as the phase rotation granularity that meets the index requirements.

[0069] Taking a phased array with a residual phase percentage of 4.5% and a far sidelobe bulge index of 2.5dB as an example, this further illustrates how to determine the phase rotation granularity that meets the index requirements. First, find the residual phase percentage closest to and greater than 4.5% in Table 1, which is 5%. Then, find the far sidelobe bulges in the column containing 5% in the parameter correspondence table, which are 10dB, 7dB, 3dB, 1.5dB, and 1dB respectively. Since 1.5dB < 2.5dB < 3dB, the far sidelobe bulge closest to 2.5dB and less than or equal to 2.5dB is 1.5dB. Finally, find the phase rotation granularity in the row containing 1.5dB, which is 16×16, and this is the phase rotation granularity that meets the index requirements.

[0070] S300: Divide the phased array into multiple subarrays according to the phase rotation granularity that meets the index requirements, and determine the rotation phase of each subarray.

[0071] Assuming the phase rotation granularity to meet the requirements is n×n, where n is a positive integer, then each subarray of the phased array includes n×n antenna elements, and the method for setting the rotation phase of each subarray is as follows:

[0072] Each subarray's antenna elements are divided into four parts, with all elements in each part having the same phase, and any two adjacent parts differing in phase by 90°. For example, the four parts might have phases of 0°, 90°, 180°, and 270°, forming a clockwise rotation. Figure 4 The diagram shows an exemplary rotation phase of a subarray of a phased array with a phase rotation granularity of 4×4.

[0073] S400: Apply the determined rotation phase to each subarray of the phased array.

[0074] Once the rotation phase of each subarray is determined, it can be applied to each subarray of the phased array, causing the phased array to operate according to the determined phase rotation granularity, thereby achieving communication. For example... Figure 5 As shown, in the phased array using the method of the present invention, the amplitude attenuation of the side lobes in the range of 60 to 90 degrees away from the main lobe is lower than the attenuation index of -30 dB. Only the amplitude attenuation at ±47 degrees away from the main lobe is -25.2342 dB, which is slightly higher than the attenuation suppression index of -30 dB, and the bulging of the far sidelobe is significantly improved.

[0075] The method for suppressing distal sidelobe bulge in this invention can significantly improve distal sidelobe bulge, thereby enhancing communication performance.

[0076] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. Various variations can be made to the above embodiments of the present invention. That is, all simple and equivalent changes and modifications made based on the claims and description of this invention fall within the protection scope of the claims of this patent. All aspects not described in detail in this invention are conventional technical content.

Claims

1. A method for suppressing the bulge of the far sidelobe in a phased array, characterized in that, Includes the following steps: S100: Set the phase rotation granularity of the phased array to 2×2 and measure the percentage of residual phase of the phased array. S200: Determine the phase rotation granularity of the phased array to meet the index requirements based on the residual phase percentage of the phased array and the pre-given far sidelobe bulge index. S300: Divide the phased array into multiple subarrays according to the phase rotation granularity that meets the index requirements, and determine the rotation phase of each subarray; S400: Apply the determined rotation phase to each subarray of the phased array; Step S100 specifically includes: S110: Based on the 2×2 phase rotation granularity, the phased array is divided into multiple 2×2 subarrays, each of which includes 2×2 adjacent antenna elements. S120: For each 2×2 subarray, an excitation is applied to each antenna element of the 2×2 subarray. The excitation amplitude of each antenna element is 1, and the phases are 0, 90, 180 and 270 degrees, respectively. S130: Measure the phase at the air interface of each antenna in each 2×2 subarray as the residual phase of that antenna in the 2×2 subarray. S140: Determine the percentage of residual phase of each antenna in the 2×2 subarray based on the residual phase of each antenna in the 2×2 subarray; S150: Determine the residual phase percentage of the phased array based on the residual phase percentage of each 2×2 subarray; Step S140 specifically includes: S141: For each 2×2 subarray, divide the residual phase of each antenna element in the 2×2 subarray, except for the antenna element whose excitation phase is 0, by the excitation phase of the antenna to obtain the percentage of residual phase of the antenna element. S142: Calculate the average of the residual phase percentages of each antenna element in each 2×2 subarray, excluding the antenna element whose excitation phase is 0, and use it as the residual phase percentage of the 2×2 subarray. Step S150 specifically includes: Calculate the average of the residual phase percentages of each 2×2 subarray as the residual phase percentage of the phased array; Step S200 specifically includes: S210: Pre-obtain the parameter correspondence table between phase rotation granularity, residual phase percentage and distal sidelobe bulge; S220: Based on the residual phase percentage of the phased array and the far sidelobe bulge index, find the phase rotation granularity that meets the index requirements in the parameter correspondence table.

2. The method for suppressing the bulge of the far sidelobe of a phased array according to claim 1, characterized in that, The parameter table corresponds to the phase rotation granularity in the row dimension, the residual phase percentage in the column dimension, and the cell value is the far sidelobe bulge under the corresponding phase rotation granularity and residual phase percentage.

3. The method for suppressing the bulge of the far sidelobe of a phased array according to claim 2, characterized in that, Step S220 specifically includes: S221: Find the residual phase percentage in the parameter correspondence table that is closest to and greater than or equal to the residual phase percentage of the phased array, and use it as the target residual phase percentage. S222: Among the distal sidelobe bulges in the column of the target residual phase percentage in the parameter correspondence table, find the distal sidelobe bulge that is closest to the distal sidelobe bulge index and less than or equal to the distal sidelobe bulge index, and take it as the target distal sidelobe bulge. S223: Determine the phase rotation granularity of the row where the target far sidelobe bulge is located, as the phase rotation granularity that meets the index requirements.

4. The method for suppressing the bulge of the far sidelobe of a phased array according to claim 1, characterized in that, In step S300, the rotation phase of each subarray is set as follows: Each antenna element in each subarray is divided into four parts, and the phases of each antenna element in each part are the same, with any two adjacent parts having a phase difference of 90 degrees.

5. The method for suppressing the bulge of the far sidelobe of a phased array according to claim 4, characterized in that, The phases of the four parts are 0 degrees, 90 degrees, 180 degrees, and 270 degrees, respectively.

6. The method for suppressing the bulge of the far sidelobe of a phased array according to claim 4, characterized in that, The phases of the four parts are 0 degrees, 270 degrees, 180 degrees, and 90 degrees, respectively.

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